This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Expression of the human oncogene, her-2, causes selective increases in N-acetylglucosaminyltransferase T-V (GlcNAc T-V) mRNA and activity. Histological studies of breast tissue using a plant lectin that binds to the product of GlcNAc T-V show that the product is absent from non-diseased breast tissue, but is expressed when cells appear neoplastic. The GlcNAc T-V product increases in expression during tumor progression. This project focuses on identifying particular glycoproteins in breast biopsy tissue that express the GlcNAc T-V product in order to define possible biochemical tumor markers for breast carcinoma. To identify these glycoproteins, two-dimensional isoelectric focusing/SDS-PAGE techniques and LC-Q-TOF techniques are being used. After separation and electroblotting to PVDF membranes, labeled plant lectins are used to identify unique glycosylation patterns on the blotted glycoproteins.